A still image taken from video shows police officers at a shooting scene at Clackamas Town Center in Portland, Oregon. A gunman opened fire inside an Oregon shopping mall on Tuesday in the middle of the busy Christmas shopping season.

The gunman and two others were killed in a shooting on Tuesday at the Clackamas Town Center shopping mall just south of Portland, Oregon, police said.

One other person was wounded in the shooting and was transported to a hospital where the individual was treated for traumatic injuries, said Clackamas County Sheriff's spokesman James Rhodes.

"I can confirm that we believe at this point that there was one and only one shooter involved and that shooter is deceased," Rhodes told reporters. "In addition to that we have at least one patient who was taken from the mall with a traumatic injury and at least two that were deceased in addition to the shooter."